Blocker synchronizer



Patented Dec. 23, 1941 n y 2,267,452

. UNIT D NT OFFICE i Chrysler Gorporation, Highland Park, Mich., a i corporation of Delaware f Application January 26, 1939, Serial No. 252,871

iioi nns. (.01. r9243) a This invention relates to blocker synchron- .In'the drawing'I have illustrated my invention izers for clutching mechanisms. 1 i g in connection with the second and direct speed ,One object of my invention is to provide a drives of-a conventional transmission Aalthough U simplified mounting for the blocker sy nchronmy blocker synchronizer may be used wherever p izer on the companion synchronizing parti 5 blocker clutching is desired.

, Another object of my invention is to provide The transmission comprises the usual driv an operating assembly of the blocker synchroning shaft lfl'carryingthemain drive pinion ll izer and companion frictionally engaged part so meshing with countershaft gear l2. The counarranged that the blocker has unrestricted blocktershaft l3 carries a' gear l4 meshing with the ing rotation. f i second speed gear. l'5 which istloose on the trans- V A further object is to provide means for lockmission output shaft I6. ing the frictionally engaging parts of a blocker o .Splined at H to shaft l6 and preferably fixed synchronizer together, the locking means being by rings 18-, 19 against movement axiallyofthls releasable when desired to disassemble the blockshaft is a hub having an outer annular rim er from the companion friction part. i 2| extending axially beyond the body portion of It has heretofore beenproposed to mount the the hub and formed with. a series of axially exblocker-for movement with a 'sliding hub, the tending external teeth 22 engaged by the inblockerand hub being assembled as aunit. Such ternal teeth 23 of a shift clutch member or arrangement restricts free blocking rotation of sleeve 24. i l r i the blocker owing tothe frictional'engaging pres- Gear I5 has aforwardlyextending portion l5 sure between the hub and blocker 'at the time formed with a series of external clutching teeth ofengagement of the friction synchro'nizing'surand a irictionclutching cone surface 26. faces and such prior devices often fail to per- 3 Gear I llikewise has a rear extension ll formed form the desired synch o i g and b ock with clutching teeth2'l and cone surface 28, functions. With my invention, the blocker is free 25 the sleeve teeth-23 being selectively engageable from such frictional n m t wi h he hu either with teeth 25 or 21 when the sleeve 24 is p at e e Of agement of the friction sur shifted rearwardly or forwardly "to respectively 1 faces andthe hub is preferably fixed against drive shaft 16 from shaft lllin the-second or axial movement, the hub rotatably limiting the direct speed ratios; i 3 blocker'without frictionally restricting free rotae As a means of frictionallysynchronizing shaft tion ofthe blocker. I6 and hub 20 with gear l5 or gear Hand pre- This inven i n re in s r lto h s iect ventingjthe positive clutching of the sleeve 24 matt'erofmycopending application" Serial No. with teeth 25 or 21 prior. to synchronization, I 1 34 fild'Decembel 93 Which iS a provide blocker synchronizers in the form of fiinuatibii in P Q- 08J fi rings 28, 29' respectively formed-with blocker tober 29, 1936. teeth 30,3l of the same diametrical pitch as Further objects vantages of my inventhe teeth 23, 25 and 21 and respectively disposed t on W e pp 'fl e following de a between teeth 23 and teeth 25 and 21 as shown a description of several embodimentsthereof.refi Fig; 2 so that'th bl -t t 111 pres e e e being had he accompanying drawing .40 vent shift of the sleeve until the .parts to be posiinwhich? 1 V r tively clutched are synchronized. Fig. lis a'sectional elevational view of a por-. Each blocker 28; 29 i formed with a-cup 32 tion of a standard tran mission w h y invenpreferably threaded .to provide a friction surface tion applied thereto. which will cut through the oil film at the cones Fig. 2 is an enlarged sectional elevational 26, 28* withoutgroovingthe cones as described view of-a portion ofthe Fig. 1. transmission and claimed in my aforesaid copending applicashowing my blocker synchronizerh tion. The threads are preferably of ,a left hand Fig. 3 is a transverse sectional view taken as .to assist in the release of the blockers after indicated by line 3 -3 on Fig. 2; they perform. theirfunctions. 'The'blockers 28,

Fig. 4 is anenlarged' fragmentary sectional .70 29 are. respectively mounted, on. th cone porview of a portion-of the Fig. 2 structure. tionsof gears l5 and ll asa fixed sub-assembly Fig. 5 is a view corresponding to Fig. 4 but by asnap ring 33 .whichseats in the respective illustrating a modified arrangement. a 7 gear extensions l5 and H... Each blocker has Fig. 6 is a view corresponding to Figs. 4 and 5 .a plurality '(three being shown) of circumferbut illustrating a further modification,

entially spaced radially projecting stops 34 each tion of synchronization.

projecting with clearance 35 into an opening 36 formed by milling a radial slot through the portion of rim 2! which axially overhangs the body of the hub 20. The various teeth 30, 3|, 25, 21

tion surface at threads 32 has slight clearance with cone 26 approximately the same as a'normal good running bearing fit. Such a fit usually is in the neighborhood of .002 of an inch such as would be provided at gear IS on shaft l6. Under such conditions the blocker 28 will be rotatably dragged with gear IS, the stops 34 engaging one side or the other of their associated slots 36 to maintain teeth 30 out of alignment with the sleeve teeth 23 so as to insure the blocking action whenever the hub 20 and gear l5 are rotating at different speeds. .The blocker 28 has its sole support on the member which rotates it into blocking position, the blocker having clearance with the hub at HI and 282.

Blocker 28 has only slight'movement axially rearwardly, such movement (usually in the expand until it snaps into groove 4|. The groove 4| has axial clearance at 42 sufficient to accommodate the slight axial movement of the blocker rearwardly when surfaces 32 and 26 are frictionally engaged under synchronizing pressure.

In Fig. 6 the arrangement is similar to Fig. 5 except that the forward face 43 of the corresponding groove 4| is inclined sufficiently to wedge the ring 33' outwardly if the blocker 28 is pulled forwardly thereby permitting disassembly of the blocker from the gear "5". The inclinascribed, a first rotatable structure having externeighborhood of .007 to .008 of aninch) occurring when surface 32 is frictionally forced against surface 25 during the synchronizing action which occurs when sleeve 24 is shifted rearwardly for second speed. When the sleeve is thus shifted, teeth 23 engage the cammed ends 31 of blocker teeth 30 toexert synchronizing pressure at friction surfaces 32, 26. The synchronization is, practically speaking, almost instantaneous whereupon the sleeve teeth 23 can then force blocker teeth 30 into axial alignment therewith to permit the sleeve teeth to engage teeth 25 with'' out clashing or damaging the teeth. As soon as the synchronizing takes place, the blocker 28 is axially unloaded and moves forward slightly to engage ring 33.

It will be apparent that the hub 20 is free from axial frictional thrust against the blocker 28, the engagement of lugs 34 in slots 36 serving to limit rotation of the blocker with'out axially thrusting frictionally thereon. Thus the blocker rotation is assured without restriction and the blocker always performs its blocking action. If desired the surfaces 32 may be smooth to match the surfaces 25 although I have found that the threads increase the efiiciency of the servo ace 7 The mounting of blocker 29 on extension II and the functions of this blocker for controlling forward shift. of sleeve 24 are similar to the aforenal clutching teeth'and a friction surface, an axially stationary second rotatable structure having external teeth, a blocker member having a friction surface engageable with the aforesaid friction surface under relatively light blockerenergizing pressure and blocker teeth axially between the teeth of said first and second. structures, means for driving said blocker member venting shift of said sleeve into said clutching engagement prior to approximate synchronization of said structures, and means for locking said blocker member on said first structure with said friction surfaces engaged under said blocker-energizing pressure.

2. In a synchronizer of the character described, a rotatable first structure having a set of clutch Y teeth and a synchronizing friction clutching said description in connection with blocker 23 and'n'eed not" be repeated;

In assemblying the synchronizers, blocker 28 for example is slipped over the end of extension l5 and spring'ring 33 forced over the end of the extension until it snaps into locking position, the rlng being split at 39 (Fig. 3) toaccommodatesurface, an axially stationary second structure having external teeth, a sleeve having internal teeth engaging the teeth of the second structure and adapted for shifting movement to clutch the internal teeth thereof with the clutch teeth of the first structure, a blocker synchronizing member having a synchronizing friction clutch surface engageable with the friction surface of the first structure and having blocker teeth adapted to block shifting movement of said sleeve, means for driving the synchronizing member with the second structure for limited rotation relative thereto for positioning the blocker teeth in blocking relationship with respect to the teeth of the sleeve, the teeth of the sleeve when the latter is shifted engagingthe blocker teeth to effect synchronizing engagement of the friction surface of the blocker member with the friction surface of the first structure, said blocker teeth accommodatingshiftof said sleeve after syn- 3, In a-clutching device of the character described, a first rotatable structure having external' clutching teeth and a friction surface, a

second rotatable structure having external teeth, a blocker member having a friction surface engag'eable with the aforesaid friction surface and,

blocker teeth axially between the teeth of said first and second structures, means for driving said blocker member from said second structure with clearance accommodating limited rotation of the blocker member relative to said second the external teeth of said second structure and shiftable to clutchingly engage the teeth of said first structure the ends of said blocker teeth locking said blocker member on said first structure. with said friction surfaces engaged under relatively light pressure sufiicient to drag said blocker member with said first structure, and thereby take up said clearance at said driving means prior to shift of saidsleeve.

4. In a clutching device of the character described, a first rotatable structurehaving external clutching teeth and a friction surface, an axially stationary second rotatable structure havstructure, a sleeve having internal teeth engaging w scribed, a first rotatable structure having a clutching part, and a friction surface, ablocker having a blocking part and a friction surface,

the blocker and-first structure each having an annular recess formed therein, each recess having wall portions relatively opposed in the direction' of the axis of rotation of the first structure, a locking ring engagingthe opposed wall portions of one of said recesses andprojecting into the other of said recesses in engagement with one'of the opposed wall portions of said bther recess to mount the blocker on the first structure to maintain. relatively light engagement of said friction surfaces for urging rota-' tionrof the blocker with the first structure, a sec- -ond rotatable structure,a' clutching structure rotating withthe second structure and adapted for shift to clutch" with said clutching. part of the first structure when the speeds of rotation of the first and second structures are approximately the same, means rotatably connecting the blocker with one of the last two saidstructures and accommodating limited rotation of the blocker relative to this structure for disposing said block- 'ing part in blocking relationship'with respect to the clutching. structure prior to shift of the clutching structure and for disposing said blocking externalteeth, a blocker member having a friction surface engageable with the aforesaid jfriction surface and blocker'teeth' axially betweenthe teeth of said first and second struc- 1 tures, means for" driving said blocker member from said second structurewith clearance'ac- I commodating limited rotation of the blocker member relative to said second structure, a sleeve having internal teeth engaging the external teeth of said second structure and shiftable to clutchingly engage the teeth of said first structure, the ends of said blocker teeth engaging the ends of the teeth of said sleeve and preventing shift of" said sleeve into said clutching engagement prior to approximate synchronization of said structures, and a locking ring for holding the blocker member on the first structure with said friction surfaces engaged sufliciently to urge rotation of the blocker member with the first structure prior to shiftof said sleeve.

recesses acting to mount the blocker on the first structure to maintain relatively light engagement of said friction surfaces for urging rotation of the blocker with the first structure, a second said other recess prior to shift of the clutching part out of said blockingrela'tionship thereby to permit shift of the clutching structure as aforesaid when the first and second structures are rotatingat approximately thesame speed, said locking ring being free from engagement with the other of the opposed wall portions of ing structure, and means for fixing the second structure against movement in the direction of its axis of rotation. v 7. In a clutching device of the character described, a first' rotatable structure having a clutching part and a friction surface, a blocker having a blocking'par't and a friction surface engageable with the friction surface of the first structure, means extending across, and disposed between the ends of, the friction surfaces aforesaid for connectingthe blocker as a unitary assembly with the first structure, a second rotatable structure, means drivingly connecting the part to clutch with said clutching part when the blocker with" the second structure and accommodating limited relative movement therebetween, and a shift sleeve driven withthe second structure and shiftable under control of said blocking speeds of rotation of said structures are approximately the same. I

8. In a clutching device of the character described, a first rotatable structure having a rotatable structure, a clutching structure rotating with the second structure and adapted for shift to clutch with said clutching part of the first structure when the speeds of rotation of the first and second structures are approximately the' same, and means rotatably connecting the blocker with one of the last two said structures and accommodating limited rotation of the blocker relative to this structure for disposing said blocking part in blocking relationship with respect to the clutching structure prior to shift of the clutching structure and for disposing said blocking part out of said blocking relationship thereby to permit shift of the clutching structure as aforesaid when thefirst and second structures are rotating 'at approximately the same speed.

6. In a clutching device of the character declutching part and a friction surface, a blocker. having a blocking part and a friction surface, means for connecting the blocker as a unitary assembly with the first structure, a second rotatable structure, means drivingly connecting the blocker with the second structure and accommodating limited relative movement rtherebe- 9 tween, and a shift sleeve driven with the second structure and shiftable under control of said blocking part to clutch with said clutching part when the speeds of rotation of said structures are approximately the same, the blocker and the first structure each having an annular recess adjacent] their respective friction surfaces, said blocker connecting means comprising a locking ring in said annular recesses.

9. In a clutching device of the character described, a first rotatable structure having a clutching part and a friction surface, a blocker having a blocking part and a friction surface,

means for connecting the blocker as a unitary assembly with the first structure, a second rotatable structure, means drivingly connecting the blocker with the second structure and ac.-

'commodating limited relative movement there- 'between, and a shift sleeve driven with the secondstructure and shiftable under control of said blocking part. to clutch with said clutching part i whenthe speeds of rotation of said structures are approximately the same, the blocker and the first structure each having an annular recess ad- "jacent their respectively friction surfaces, said blocker connecting means comprising a locking ring in said'annular recesses, one of said recesses .be positivelyclutched; one of said structures having a set of clutch teeth and a friction surface, a clutching sleeve drivingly carried by the having a wall thereof inclined to radially stress 7 said locking ring in response to axial displacement of the blocker relative to the first structure whereby to facilitate disassembly of the blocker from the first structure. 7

10. In a clutching device, a first rotatable structure having a positive clutching part and a frictionsurface, a blocker having a blocking part and a friction surface engaging the friction surface of thefirst structure, one of said friction surfaces comprising threads engaging the other of said friction surfaces, means extending between the blocker and the first structure for holding the blocker-in assembled relationship with respect to the first structure such that said threaded surface is'constantly frictionally engaged with the said other friction surface, a second rotatable structure, means drivingly connecting the blocker with the second structure and accommodating other of said structures and shiftable axially to clutch with said teeth, a blocker member adapted to engage said friction surface under relatively light blocker-energizing pressure and having blocker means, said blocker member having a rotatable connection with said other structure accommodating limited rotation of the blocker member relative to said other structure for accommodating positioning of said blocker means in blocking relationship with respect to said clutching sleeve when said structures are rotating at relatively different speeds and for disposing said blocker means out of said blocking relationship thereby to accommodate shift of said clutching sleeve as aforesaid when said structures are rotating at approximatelyrthe same speed, and means locking said blocker member on said friction surface in engagement therewith under saidrelatively light blocker-energizing pressure whereby to induce said positioning of said blocker member in said blocking relationship prior to clutching shift of said clutching sleeve.

' OTTO E. FISHBURN. 

